The Torre de Hércules (or Tower of Hercules), a stone lighthouse perched at the edge of town, is the oldest Roman-built lighthouse still in use today. It’s been altered a bit—the original tower had an external staircase open to the elements, but in 1788 King Carlos III had the structure enclosed in stone. Local legend says that Hercules built the original tower atop the grave of a giant who was slain after a battle that lasted three days.